William E. Bradley

Evaluation of erectile dysfunction with continuous monitoring of penile rigidity.

Measurement of nocturnal penile tumescence or circumferential expansion is a valuable method for the diagnosis of erectile impotence. However, only a few investigations have been made of penile rigidity during tumescence with a single isolated measurement. A new method of continuous and simultaneous recording of nocturnal penile rigidity and circumferential expansion (tumescence) was used in 105 patients with erectile impotence. The method provided several findings concerning nocturnal penile erection. Circumferential expansion was not always accompanied by penile rigidity. A dissociation of rigidity between the tip and base of the penis was observed in some patients. Shortened episodes and low amplitude of rigidity also were seen. Of 11 patients with psychogenic impotence diagnosed by conventional methods 3 (27.3 per cent) showed abnormal nocturnal rigidity and 8 of 94 (8.5 per cent) with organic impotence diagnosed by conventional methods showed normal nocturnal rigidity. Because of its ambulatory character the continuous measurement of nocturnal penile rigidity is of value in defining features of nocturnal penile erection and differentiating psychogenic from organic impotence.

Evoked Responses from the Pudendal Nerve

AbstractEvoked responses on stimulation of the dorsal nerve of the penis were recorded in a group of healthy male subjects and in patients with distinct neurologic lesions. Responses were recorded over the bulbocavernosus muscle by a new percutaneous method, and over the spinal cord and cerebral cortex by computer averaging of multiple stimuli applied to the pudendal nerve. The neurologic lesions in patients with bladder symptoms secondary to diabetic peripheral neuropathy, myelopathy owing to multiple sclerosis and Parkinson’s disease were confirmed using these tests, as well as cystometry and somatosensory evoked responses from the posterior tibial nerve.

The Etiology of Detrusor Hyperreflexia in Patients with Infravesical Obstruction

Bladder function was studied in 44 patients with bladder outlet obstruction by gas cystometry, integrated sphincter electromyography and uroflowmetry. Of these 44 patients 18 demonstrated detrusor hyperreflexia on cystometry. To identify the prostate as a possible source for triggering sensory stimuli pharmacologic ablation with lidocaine was performed through a perineal approach in 11 patients with hyperreflexia. Prostatic block eliminated hyperreflexia in 10 of 11 patients and had no effect in 4 patients with a normal cystometrogram. We believe that this study lends support to the concept that sensory stimuli from an anatomically altered prostatic urethra induces detrusor hyperreflexia. This suggests that permanent ablation of sensory stimuli from the prostate in patients with outlet obstruction would be of benefit.

Penile Neuropathy in Insulin-Dependent Diabetes Mellitus

The dorsal nerve of the penis has been linked closely to penile erection and response. We measured the nerve conduction velocity of the dorsal nerve of the penis, latency of the bulbocavernosus reflex and pudendal evoked potential in 23 normal men and 20 insulin-dependent diabetics with impotence. The conduction velocity of the dorsal nerve of the penis was significantly slower in diabetic than in normal men and passive gentle elongation of the penis by weight stretching enhanced the slowing. In contrast, the bulbocavernosus reflex and pudendal evoked potential showed no significant differences between the 2 groups. We demonstrate the potential usefulness of measurement of the conduction velocity of the dorsal nerve of the penis in the detection of penile neuropathy.

Measurement of the Conduction Velocity of the Dorsal Nerve of the Penis

We describe an orthodromic nerve conduction technique of the dorsal nerve of the penis in 27 normal men. The mean compound nerve action potential was 12.0 plus or minus 6.1 microV. The nerve conduction velocity was 24.4 plus or minus 3.2 milliseconds when the penis was at rest. Gentle stretch of the penis with a 1-pound weight increased the conduction velocity to 33.0 plus or minus 3.8 milliseconds. Since the dorsal nerve of the penis has an important role in erection the new methodology may be useful in the evaluation of male impotence.

Urodynamics: Continuous Monitoring

Continuous ambulatory monitoring of intravesical and intraurethral pressures was done in 26 patients using a portable tape recorder, a specially designed urethral catheter and pressure sensitive catheter tip transducers. With this technique we overcame some of the difficulties encountered with previously described recording systems for monitoring intravesical and intraurethral pressures on a continuous basis. Pressure changes in the urethra and bladder were recorded in response to various resting and stressful situations, with the patient in a natural environment and with freedom of activities of daily living. A correlation was established between the symptoms and the results of continuous monitoring, at the same time unmasking the discrepancies between the results of cystometry and the urinary complaints of the patient.

Cortical evoked potentials on stimulation of pudendal nerve in women

Somatosensory evoked potentials were recorded in five normal women on percutaneous stimulation of the pudendal nerve. A consistent response was obtained over the scalp 2 cm behind the Cz electroencephalographic recording site. The latency of onset of this response had a mean value of 33 msec, and the mean latency of the first positive peak was 39.6 msec. This test has potential clinical value in the evaluation of patients with bowel, bladder, or sexual dysfunction when a neurologic causation is suspected.

Penile Electrodiagnosis. Value of Bulbocavernosus Reflex Latency Versus Nerve Conduction Velocity of the Dorsal Nerve of the Penis in Diagnosis of Diabetic Impotence

The nerve conduction velocity of the dorsal nerve of the penis was evaluated with a direct measuring technique in impotent men with and without diabetes mellitus. The average nerve conduction velocity was 37 M. per second in impotent diabetics and 45 M. per second in nondiabetics. The latency of the bulbocavernosus reflex showed no significant difference between the groups and was within normal limits. The measurement of the nerve conduction velocity of the dorsal nerve of the penis is a valuable test for assessment of impotence in patients with diabetes mellitus.

Continuous monitoring of bladder and urethral pressures: new technique

A new technique for continuous monitoring of intravesical and intraurethral pressures was developed and utilized in a group of male patients to overcome the disadvantages associated with previously employed liquid and air-coupled systems. This technique permitted recording under physiologic conditions and provided information on a continuous basis concerning changes in the intravesical and intraurethral pressures in patients with multiple urologic symptoms. With further modifications this technique promises to further our understanding of the dynamics of the lower urinary tract under various conditions of stress.